עבודה זו נתמכה על ידי מענק הפרויקט טייס ממרכז CREH ממומן על ידי NIEHS ועל ידי הלאומי מדעי הטבע קרן של סין (מספר 31572626).

ניסויים בבעלי חיים כל הוצאו להורג בדרישות ההנחיות הרלוונטיות כל, תקנות וגופים רגולטוריים. פרוטוקול להיות הפגינו בוצעה תחת הדרכה ואישור של טיפול בעלי חיים מוסדיים ושל שימוש הוועדה (IACUC) של טקסס A & M המכון ללימודי רפואה גנומית.
1. פתרון הכנה
<ol><li>לדלל תמיסת מלח מאוזנת של האנק x 10 ל- x 1 עם כפול מזוקקים H2O, ולאחסן ב 4 º C.</li>
	<li>הכינו את הפתרון בידוד על-ידי הוספת HEPES (10 מ מ), MgCl2 (1 מ מ) וגלוקוז (5 מ מ). להתאים את ה-pH ל 7.4 ולשמור על קרח.</li>
	<li>להכין את הפתרון collagenase מן collagenase Type 4. הערה: באופן ספציפי, collagenase Type 4 מכיל 160 U לכל מ ג של משקל יבש. 1 גר' collagenase Type 4 הוא מדולל 5 מ"ל כפול מזוקקים H2O עם ריכוז של 200 מ"ג/מ"ל. 2 מיליליטר Collagenase מדולל מתווסף 30 מ ל הקרח בידוד קר פתרון, 6 מ של פתרון collagenase מועבר שפופרת 50 מ עבור כל עכבר.</li>
	<li>הכינו את הפתרון שטיפת על-ידי הוספת 1 מ"מ CaCl2 הפתרון בידוד.</li>
	<li>הכינו את פתרון טיהור בעזרת פתרון diatrizoate polysucrose קר/נתרן (1.1119 g/mL, 5 mL).</li>
	<li>להכין 500 מ"ל של איון תרבות בינוני על-ידי הוספת-גלוטמין (20 מ מ), פניצילין (100 U/mL), סטרפטומיצין (100 µg/mL), סרום שור עוברית (FBS) (10%) לתוך RPMI בינונית.</li>
	<li>להכין את הפתרון DCFH-DA מניות על ידי המסת אבקה מים מזוקקים-200 מיקרומטר, חנות ב-20 ° C. הערה: האבחון מכתים הפתרון נעשה טרי על ידי דילול לפתרון מניות DCFH-DA הריכוז הסופי של 5 מיקרומטר ב- RPMI. ריאגנט הזה צריך להיות מוגן מפני אור.</li>
</ol>2. ניתוח הכנה
<ol><li>Intraperitoneally להזריק (I.P.) עכבר עם avertin (2.5% avertin, 0.4 מ ל/20 גרם). אחרי העכבר הוא מורדם לחלוטין, כבר לא מגיב כדי הינד רגל צובט, המתת חסד בעכבר והזז מכסה המנוע ביולוגי.</li>
	<li>הנח את העכבר לאללה עם הצד הבטן פונה כלפי מעלה, לרסס את העור עם אתנול 70% עבור עיקור.</li>
	<li>פתיחת חלל הבטן עם 1 ס מ U-החתך על הבטן העליונה ומשכו את העור בכיוון rostral החזה כדי לחשוף את חלל הבטן.</li>
</ol>3. לבלב זלוף והסרה
<ol><li>כמופיע באיור1, למצוא את המיקום של ampulla. השתמש זוג מלקחיים מעוקל נכנעתי התריסריון קרוב המיקום של הסוגר של Oddi. להשתמש עוד זוג מלקחיים מעוקל תהדק את הקיר התריסריון כדי לחסום את המעבר מרה תריסריון. הערה: Ampulla לא הוכנס בשלב זה. שלב זה נועד לחסום את המעבר מרה תריסריון.</li>
	<li>למקם מחדש את העכבר עם הראש הפרוקסימלית ואת כפות הרגליים דיסטלי לגבי החוקר.</li>
	<li>למצוא את צינור המרה, לאט להזריק 3 מ"ל של collagenase פתרון בעזרת מזרק 5 מ ל ומחט 30 גרם. ודא שאת צינור המרה והלבלב הם בניפוח לאחר הזריקה.</li>
	<li>הסר את הלבלב נפוחה באמצעות מלקחיים מעוקל מספריים בסדר כדי להפרידו מן יורד קולון, המעיים, קיבה, טחול. למקם את הלבלב צינור 50-mL המכיל 3 מ"ל של פתרון collagenase ולשמור אותו בקרח.</li>
</ol>4. לבלב עיכול
<ol><li>מקם כל שפופרת 50-mL לתוך אמבט מים 37 º C. תקופת דגירה של 15-20 דקות (זמן משתנה עם זן, הגיל של העכברים).</li>
	<li>רטט הצינור באמצעות מערבולת.</li>
	<li>בריכה 4-5 הלבלב מתעכל במסננת גדולה כיור סטרילי והשתמש סקופ כדי להפוך הלבלב להתפרק ביסודיות. להשתמש בכוח pipette התאים מתעכל מהמסך 23 גרם 10 מ"ל ומחט המזרק המכיל שטיפת פתרון. לאסוף את הפתרון לשטוף בצינור 50-mL.</li>
	<li>Centrifuge הצינורות ב g x 97 ב 4 ° C עבור 1 דקות, decant את תגובת שיקוע.</li>
	<li>להוסיף 25 מ של פתרון לשטיפת צינורות, מחדש להשעות את הרקמה על ידי עדין vortexing. ספין לאורך הרקמות ב g x 97 ב 4 ° C עבור 1 דקות, decant את תגובת שיקוע. חזור על 3 פעמים. להיזהר לא להוציא את הרקמה pelleted.</li>
</ol>5. טיהור של איים קטנים
<ol><li>להוסיף 10 מ של פתרון טיהור בגדר רקמות שטף, resuspend בעדינות את התוכן.</li>
	<li>בעדינות כשכבת-על 5 מ של בידוד פתרון על הפתרון טיהור. הקפד לשמור על ממשק נוזלי חדה בין שני הפתרונות.</li>
	<li>Centrifuge את הצינור 560 x g ב 4 מעלות צלזיוס למשך 15 דקות עם האצה איטית, בלי בלמים. להוסיף את פיפטה לתוך הממשק ולאסוף את השכבה איים קטנים לתוך צינורות 50 מ ל חדש.</li>
	<li>לשטוף את איונים כפי שמתואר בשלב 3.5.</li>
</ol>6. ציפוי וטיפול של תאי איון
<ol><li>Resuspend ע ב 10 מ"ל של איים קטנים תרבות פתרון מערבבים היטב ובעדינות במקום 100 µL טוב עם פיפטה רב-ערוצי על צלחת 96-ובכן. במקום כ 5 איים לכל 96. טוב.</li>
	<li>מקם את הצלחת בחממה תרביות רקמה במשך 12 שעות.</li>
	<li>Centrifuge (112 x g) של צלחת 96-ובכן ולהסיר המדיום תרבות.</li>
	<li>לדלל כימיקלים סביבתיים במדיום תרבות איונים. להוסיף 100 µL של כל אחד מדלל כימי לתוך בארות נפרדים של הצלחת. Resuspend איים על כל היטב, תקופת דגירה של 12 שעות ב 37 מעלות צלזיוס (הריכוז משתנה לחומרים סביבתיים שונים).</li>
</ol>7. ROS מכתים ומדידה
<ol><li>לאחר הטיפול איונים, לשטוף עם PBS 1 x (200 µL עבור כל 96-ובכן). הערה: ריכוז הכימיקלים הוא כדלקמן: AFB1: 3 מיקרומטר, מסוג אטרזין: 100 מיקרומטר, BaP: 10 מיקרומטר, BPA: 100 מיקרומטר, β-אסטרוגן, PCB126: 10 מיקרומטר, Nonylphenol ו BPA: 100 מיקרומטר.</li>
	<li>השתמש N-אצטיל ציסטאין (NAC) כ נוגד חמצון כדי להרוות ROS. להוסיף 5 מ מ של NAC מדלל כימיות הנוצרות על-ידי ROS, תקופת דגירה של 12 שעות ב- 37 מעלות צלזיוס.</li>
	<li>Centrifuge את הצלחת 96-ובכן ב g 112 x, דגירה עם 5 מיקרומטר פתרון של בדיקה פלורסנט (H2-DCFH-DA מומס RPMI מדיה) ב 37 מעלות צלזיוס למשך 60 דקות.</li>
	<li>לשטוף את התאים איון שטופלו 3 פעמים עם PBS ולמדוד את זריחה עם קורא microplate-488 ננומטר. הערה: ההצטברות של DCF בתאים יכול להימדד על-ידי עלייה בזריחה ב- 530 ננומטר כאשר המדגם הוא נרגש-488 ננומטר.</li>
	<li>מבצע אינסולין הגלוקוז-גירוי הפרשת (GSIS) assay9 xenobiotic בתדר ROS מטופלים איונים ושל לא מטופל כדי למדוד את ההשפעות xenobiotic על תפקיד פיזיולוגי באיי לנגרהנס.</li>
</ol>

<ol>
	<li>Maruthur, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+growing+prevalence+of+type+2+diabetes:+increased+incidence+or+improved+survival?.">The growing prevalence of type 2 diabetes: increased incidence or improved survival?.</a> Current diabetes reports. 13 (6), 786-794 (2013).</li><li>Houstis, N., Rosen, E. D., Lander, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactive+oxygen+species+have+a+causal+role+in+multiple+forms+of+insulin+resistance.">Reactive oxygen species have a causal role in multiple forms of insulin resistance.</a> Nature. 440 (7086), 944-948 (2006).</li><li>Ma, Z. A., Zhao, Z., Turk, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+dysfunction+and+beta-cell+failure+in+type+2+diabetes+mellitus.">Mitochondrial dysfunction and beta-cell failure in type 2 diabetes mellitus.</a> Exp Diabetes Res. , 703538 (2012).</li><li>Valavanidis, A., Vlahogianni, T., Dassenakis, M., Scoullos, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+biomarkers+of+oxidative+stress+in+aquatic+organisms+in+relation+to+toxic+environmental+pollutants.">Molecular biomarkers of oxidative stress in aquatic organisms in relation to toxic environmental pollutants.</a> Ecotoxicology and environmental safety. 64 (2), 178-189 (2006).</li><li>Robertson, R. P., Harmon, J., Tran, P. O., Tanaka, Y., Takahashi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucose+toxicity+in+&#946;-cells:+type+2+diabetes,+good+radicals+gone+bad,+and+the+glutathione+connection.">Glucose toxicity in &#946;-cells: type 2 diabetes, good radicals gone bad, and the glutathione connection.</a> Diabetes. 52 (3), 581-587 (2003).</li><li>Kaneto, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+stress+induces+p21+expression+in+pancreatic+islet+cells:+possible+implication+in+beta-cell+dysfunction.">Oxidative stress induces p21 expression in pancreatic islet cells: possible implication in beta-cell dysfunction.</a> Diabetologia. 42 (9), 1093-1097 (1999).</li><li>Maechler, P., Jornot, L., Wollheim, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogen+peroxide+alters+mitochondrial+activation+and+insulin+secretion+in+pancreatic+beta+cells.">Hydrogen peroxide alters mitochondrial activation and insulin secretion in pancreatic beta cells.</a> Journal of Biological Chemistry. 274 (39), 27905-27913 (1999).</li><li>Gao, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+palmitate+on+hepatic+insulin+resistance+are+mediated+by+NADPH+Oxidase+3-derived+reactive+oxygen+species+through+JNK+and+p38MAPK+pathways.">The effects of palmitate on hepatic insulin resistance are mediated by NADPH Oxidase 3-derived reactive oxygen species through JNK and p38MAPK pathways.</a> Journal of Biological Chemistry. 285 (39), 29965-29973 (2010).</li><li>Efendi&#263;, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pancreastatin+and+islet+hormone+release.">Pancreastatin and islet hormone release.</a> Proceedings of the National Academy of Sciences. 84 (20), 7257-7260 (1987).</li><li>Tian, Y., Ke, S., Denison, M. S., Rabson, A. B., Gallo, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ah+receptor+and+NF-&#954;B+interactions,+a+potential+mechanism+for+dioxin+toxicity.">Ah receptor and NF-&#954;B interactions, a potential mechanism for dioxin toxicity.</a> Journal of Biological Chemistry. 274 (1), 510-515 (1999).</li><li>Cui, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pregnane+X+receptor+regulates+the+AhR/Cyp1A1+pathway+and+protects+liver+cells+from+benzo-[&#945;]-pyrene-induced+DNA+damage.">Pregnane X receptor regulates the AhR/Cyp1A1 pathway and protects liver cells from benzo-[&#945;]-pyrene-induced DNA damage.</a> Toxicology Letters. 275, 67-76 (2017).</li><li>Li, L. A., Wang, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PCB126+induces+differential+changes+in+androgen,+cortisol,+and+aldosterone+biosynthesis+in+human+adrenocortical+H295R+cells.">PCB126 induces differential changes in androgen, cortisol, and aldosterone biosynthesis in human adrenocortical H295R cells.</a> Toxicological Sciences. 85 (1), 530-540 (2005).</li><li>Asahi, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bisphenol+A+induces+endoplasmic+reticulum+stress-associated+apoptosis+in+mouse+non-parenchymal+hepatocytes.">Bisphenol A induces endoplasmic reticulum stress-associated apoptosis in mouse non-parenchymal hepatocytes.</a> Life sciences. 87 (13), 431-438 (2010).</li><li>Szot, G. L., Koudria, P., Bluestone, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+pancreatic+islet+isolation.">Murine pancreatic islet isolation.</a> JoVE (Journal of Visualized Experiments). (7), e255 (2007).</li><li>Kirstetter, P., Lagneau, F., Lucas, O., Krupa, Y., Marty, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+endothelium+in+the+modulation+of+isoflurane-induced+vasodilatation+in+rat+thoracic+aorta.">Role of endothelium in the modulation of isoflurane-induced vasodilatation in rat thoracic aorta.</a> British journal of anaesthesia. 79 (1), 84-87 (1997).</li><li>Brown, E., Umino, Y., Loi, T., Solessio, E., Barlow, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anesthesia+can+cause+sustained+hyperglycemia+in+C57/BL6J+mice.">Anesthesia can cause sustained hyperglycemia in C57/BL6J mice.</a> Visual neuroscience. 22 (5), 615-618 (2005).</li><li>Vaupel, D., McCoun, D., Cone, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phencyclidine+analogs+and+precursors:+rotarod+and+lethal+dose+studies+in+the+mouse.">Phencyclidine analogs and precursors: rotarod and lethal dose studies in the mouse.</a> Journal of Pharmacology and Experimental Therapeutics. 230 (1), 20-27 (1984).</li><li>Neuman, J. C., Truchan, N. A., Joseph, J. W., Kimple, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+mouse+pancreatic+islet+isolation+and+intracellular+cAMP+determination.">A method for mouse pancreatic islet isolation and intracellular cAMP determination.</a> Journal of visualized experiments: JoVE. (88), (2014).</li></ol>

המחברים מצהירים כי יש להם אינטרסים כלכליים אין מתחרים.

לצבירת ראיות מציע כי החשיפה לכימיקלים סביבתיים ממלא תפקיד חשוב בהתפתחות של T2DM. ROS ואינטראקציות-induced הוכר כגורם etiological פוטנציאליים, תורם להתפתחות של T2DM. בני אדם חשופים למגוון רחב של כימיקלים xenobiotic, ויש צורך גדול עבור מחקר חדשניים טכניקות לזיהוי ביעילות את הלבלב חשיפה לרעלים, לחקור את המנגנו?...

עולה השכיחות של T2DM הפכו משבר הבריאות העולמי בשנים האחרונות פוזות איום רציני לבריאות הציבור1. גורמים רבים נמצאו להיות מקושר סיבתי הפיתוח של T2DM, ביניהם, חוזרות ממצאים מראים כי נקודה מתכנסת אחת נפוצה עבור גורמים אלה הוא אינדוקציה של סטרס חמצוני, מה שמוביל הדור של ROS מופרז2 , 3.
מגוון רחב של כימיקלים סביבתיים לרבות Pcb, דיוקסינים BaP נמצאה לזירוז סטרס חמצוני, אשר עלול לפגום את תפקוד תאי β בלבלב, להוביל תנגודת לאינסולין ו- T2DM4. למרות הרמה פיזיולוגיים של ROS ממלא תפקיד חשוב בתאיים, חשיפה ROS שחורג הקיבולת של המערכת נוגד חמצון מתבטא הנזק לרקמות/תאים ומוביל מחלות5. תאי β בלבלב אקספרס רמה נמוכה של אנזימים נוגדי חמצון, ולכן הם מטרה רגיש ביותר נזק בתיווך סטרס חמצוני6,7. חשיפה כרונית רמות גבוהות של ROS הוכח לגרום תאי הלבלב מפגינות תפקוד5 וכן לאינסולין בכבד, רקמת שומן8.
המטרה הכוללת של הפרויקט הזה היא לפתח הנועד מבוססת תא כימיקלים המסך שלהם פוטנציאל diabetogenic מבוסס על אינדוקציה שלהם של ROS בתאי הלבלב. הלבלב חסר רעלים מטבוליים, הוא מטרה רגיש הנזק הנגרמת xenobiotic6,7. לכן, על ידי מדידת ישירות את האבחון שנוצר בתאי הלבלב, וזמינותו הזה צריך לספק הערכה ישירה של הפגיעה הנגרמת כימית בלבלב. כדי לפתח שיטה זו, אנחנו מבודדים לנגרהנס עכבר תרבותי של איון מבודד בתנאי התרבות תאים עם כימיקלים, מנוצל הדור ROS כימית-induced כמו המדידה. ההליך זה פשוטה ויעילה בזיהוי בתדר ROS חומרים כימיים איון מבודדים; זה יכול להיות פיתוח נוסף לחקירה על מנגנוני רעילות ספציפיים הלבלב חוץ גופית בתוך.

<table><tbody><tr><td>10&amp;times;Hank&amp;rsquo;s balanced salt solution&amp;nbsp;</td><td>GIBCO</td><td>14185-052</td><td></td></tr><tr><td>Collagenase Type 4</td><td>Worthington Biochemical Corporation</td><td>CLS-4</td><td></td></tr><tr><td>polysucrose/sodium diatrizoate solution&amp;nbsp;</td><td>Sigma</td><td>10771</td><td></td></tr><tr><td>2&amp;rsquo;,7&amp;rsquo;-dichlorofluorescein (DCFH-DA)</td><td>Sigma</td><td>D6883-50MG</td><td></td></tr><tr><td>fluorescence microplate reader&amp;nbsp;</td><td>Biotek</td><td></td><td></td></tr><tr><td>L-glutamine</td><td>Sigma</td><td>G8540-25G</td><td></td></tr><tr><td>streptomycin</td><td>GIBCO</td><td>15140148</td><td></td></tr><tr><td>FBS</td><td>GIBCO</td><td>26140079</td><td></td></tr><tr><td>RPMI 1640</td><td>GIBCO</td><td>11875-085</td><td></td></tr><tr><td>avertin</td><td>Sigma</td><td>T48402-25G</td><td></td></tr><tr><td>Rat/Mouse Insulin ELISA Kit</td><td>Millipore</td><td>EZRMI-13K</td><td></td></tr><tr><td>Centrifuge</td><td>Sorval</td><td>Sorval RT7</td><td>for 96-well plate centrifuge</td></tr><tr><td>Microplate reader</td><td>Biotek</td><td>Epoch 2</td><td>for fluorescence reading</td></tr></tbody></table>

a murine pancreatic islet cell-based screening for diabetogenic environmental chemicals

חשיפה לכימיקלים סביבתיים מסוימים של האדם ובעלי חיים נמצאה לגרום נזק תאי של תאי β בלבלב אשר יוביל להתפתחות של סוכרת סוג 2 (T2DM). למרות המנגנונים על הנזק תאי β כימית-induced היה לא ברור, עשוי להיות מורכב, ממצא חוזרות אחד היא כי חומרים אלה זירוז סטרס חמצוני שמוביל הדור של מינים חמצן תגובתי מוגזמת (ROS) לגרום נזק התא β. כדי לזהות פוטנציאל diabetogenic כימיקלים סביבתיים, בודדנו תאי הלבלב איון של עכברים C57BL/6 ואיון בתרבית תאים ב 96-ובכן תא תרבות לוחות; לאחר מכן, התאים איון היו עצומות עם כימיקלים, הדור ROS אותרה על ידי 2', 7'-dichlorofluorescein (DCFH-DA) הפלורסנט. באמצעות שיטה זו, אנו נמצא כי ביספנול A (BPA), Benzo [א] pyrene (BaP) ולאחר polychlorinated biphenyls (PCBs), עלול לגרום לרמות גבוהות של ROS, רומז כי הם פוטנציאלי עלול לגרום נזק תאי איון. שיטה זו צריכה להיות שימושית עבור הקרנת diabetogenic ואינטראקציות. בנוסף, התאים בתרבית איון עשוי גם להיות מותאם לניתוח במבחנה רעילות כימית-induced בתאי הלבלב.

מיקרוסקופ של איון מבודד בריא מוצג באיור 2, שבה יש איים קטנים עגולים או אליפטיים צורה עם מדים יחסית לגודל (למרות אחידות הגודל יכול להשתנות זן זן). חקרנו את הפונקציות הלבלב איון assay במבחנה הבא מאת לבודד את איון והמרצת הפרשת אינסולין בלבלב ע תרבות. <strong class=...

Watch this Scientific Journal Video about A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals at JoVE.com

A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals

כאן אנו מציגים פרוטוקול בידוד תאי הלבלב איון העכבר לסינון את inductions ROS מאת ואינטראקציות על מנת לזהות פוטנציאל diabetogenic xenobiotic כימיקלים.

הקרנה מבוססת תא מאתר הלבלב איון Diabetogenic כימיקלים סביבתיים

Exposure to certain environmental chemicals in human and animals has been found to cause cellular damage of the pancreatic &#946; cells which will lead to ...

a-murine-pancreatic-islet-cell-based-screening-for-diabetogenic

Research

JoVE Journal

Immunology and Infection

7.3K Views.  Hunan Agriculture University. כאן אנו מציגים פרוטוקול בידוד תאי הלבלב איון העכבר לסינון את inductions ROS מאת ואינטראקציות על מנת לזהות פוטנציאל diabetogenic xenobiotic כימיקלים.

Video: A Murine Pancreatic Islet Cell-based Screening for Diabetogenic Environmental Chemicals

Murine Pancreatic Islet Isolation

Hi, I am Greg Zott. I'm with the UCSF Diabetes Center in the Bluestone Laboratory, and today I'm gonna show you the process for isolating mouse eyelets. The procedure involves the injection of a collagenase solution into the pancreas of a C3 H donor mouse, where we will then remove that pancreas, digest it away, purify the eyelets on a fial gradient, and then handpick them for ultimate transplant into the kidney capsule of a diabetic NOD mouse, Which will be our recipient.Before we start this procedure, we diluted our ATE solution in a modified Hanks buffer and we have adjusted the concentration specific for the strain of mouse that we're using the C3 H.We found digests better at a 0.8 mgs per mil collagenase solution, and we will use that to inject into the common bile duct to distend the pancreas.Performing. The procedure today Will be Pavo codre of the diabetes center. He will inject, open up the mouse, expose the the intestines, and then inject into the common bile duct.We will spray down the mouse with ethanol to keep the hair down, and then we will also verify that the mouse has been sacrificed properly with a toe pinch. Pavo will now open up the mouse and exposing the intestine and the pancreas with a midline incision. The diaphragm will also be cut to verify that the mouse will be sacrificed.Before we get started, I'd like to point out some of the important structures. The stomach is lying right here with the pancreas attached underneath into the duodenum and above. This is the liver where we'll find the gallbladder and the common bile duct, which you can see right here.So what Pavo will do next is he will isolate the small intestine, find where the common bile duct enters the small intestine. Once the intestine is exposed, we clamp on either side of the common bile duct with mosquito clamps. We find that this allows more collagenates to enter the pancreas while other groups try to direct the clamp on top of the common bile duct.We find that this is a better technique in allowing enzyme to enter the pancreas. This is a gentle procedure. You don't want to tear the bowel.You wanna allow the clamps to lie gently on either side of the common bile duct. Now we will find a gallbladder, and once the gallbladder's exposed, we will use that as a guide to injecting the collagenase into the common bile duct. Powell's using a 30 gauge needle with a five cc syringe containing three mills of collagenase solution.As he's entering the common bile duct, he's distending that duct with collagenase solution and then he travels down the common bile duct till he reaches near the intestine. And as he's going down, the enzyme solutions being pumped into the injected into the pancreas. Now that the pancreas is inflated with collagenase solution, Powell's gonna remove the hemostats and then remove the pancreas from the the mouse carefully tearing it away from the intestine.He removes it from the stomach. Okay, and then using the spleen as a handle, he lifts up the pancreas and then slowly snips it away in the common bile duct, and that's it. Pancreas is laid out and then the spleen is removed, and there he's removing the meso enteric tissue, and then the pancreas is placed in a two mill collagenase solution and a sterilized glass vial and it's placed back on Ice.The isolated pancreas that we put into the glass vials will now be placed into a 37 degree water bath for approximately 17 minutes. We placed them into a 50 mil conical rack so that they don't float up. Once during the bath, the timer starts and the digestion begins.Once the digestion time is completed, vials are removed, and then they are shaken and disrupted gently. And once the tissue starts falling apart, the vial is then placed on ice. A sterile screen is placed over a 400 mil beaker that contains washing buffer.The pancreas digest is then carefully poured over the screen into the wash buffer. For demonstration purposes, the hood has been turned off and the glass of the hood has been raised so we could see what we're doing. Once the pancreas digest is poured into the beaker, the vials are rinsed with the same washing buffer and the wash buffer placed over the screen.We have a syringe filled with washing buffer. We will use that to forcefully wash the tissue through the screen. The idea is to release any loose eyelets that are unattached to the matrix, but leaving the membranes and the undigested tissue on the screen.And when you're finished washing a tissue, this is what you usually See at the end of the procedure. The Pancreas tissue that's in the bottom of the tube will now be transferred to two 50 mil conical, and the tissue will be washed, the tissue's mixed evenly, and then distributed evenly so that we have a equal pellet volume in each tube. The beaker is now rinsed with more washing buffer.The sides are rinse so that you get all tissue that is entered the beaker again. Then it's equally distributed between each two, both 50 mil. Conical then are topped off with wash buffer.The tissue is inverted several times and then placed into a centrifuge. This is a quick spin. The centrifuge is allowed to reach a thousand RPM and then is turned off.The tissue at this time is very S eyelets are very sensitive, and you don't want to over compact them. The tubes are removed and we will do this wash step three more times. This is the end of the third wash.The components of the 50 mil conical tube are transferred to the 15 conical tube and centrifuge for a thousand RP M and then stopped. The supernat will be removed and the first part of the FI Call will be started. We are at the step where we Have our pelleted di pancreas digest.We'll resuspend that tissue so it's nice and loose to the pellets. We'll add the first density gradient, which is 1 1 0 8. We'll add five mils to each tube.The pellet is then mixed thoroughly in each of the gradients. It's important that you get good tissue distribution in your heaviest gradient. Now we will layer two mils of 1 0 9 6 density.We will then on top of that, layer two mils of 1 0 6 9 density, and then on top of that 1 0 3 7 density. It's important while you're layering the densities that you don't mix. Then all the layers have been added to the tube.And you can see this is the top of 1 1 0 8, the top of 9 1 0 9 6, the top of 1 0 6 9 and the top of 1 0 3 7. And you could see the tissue is already starting to move to its proper density even without centri fusion. The fial gradients are brought up to speed at 1800 RPM for 15 minutes, and remember to keep the brake off after the tubes are removed from the centrifuge.You can see between the 0 0 9 6 and 0 0 7 layer, there's a nice band of eyelet tissue Pablo's. Now removing the 0 3 7 layer to remove any tissue debris and DNA that might have been released during the processing. Using a sterile plastic pasture pipette, he will now remove the islet layer and transfer them to a 50 mil conical containing 25 mils of wash buffer.You want do this step quickly because fol is toxic to eyelets. We actually removed the entire 0 6 9 and 0 9 6 layer. Pavo cuts the top of the plastic pasture pipette and rinses it with wash buffer.The eyelets are then centrifuge like we centrifuge previously. Centrifuge is brought up to a Thousand RPM and then we stop it and We aspirate off. The supernatant eyelets will be washed three times with wash media.So we just completed the eyelid Isolation process we took from the digest to the fol gradient to the purified eyelets after our third wash with wash buffer, we resuspended the eyelets in our RPMI media and we played it in a tissue culture plate. These eyelets are now ready for in vitro assays or in vivo preps like eyelet Transplant.

הלבלב Murine איילט בידוד

Biology

Scaffold-supported Transplantation of Islets in the Epididymal Fat Pad of Diabetic Mice

Islet transplantation has been clinically proven to be effective at treating type 1 diabetes. However, the current intrahepatic transplantation strategy may incur acute whole blood reactions and result in poor islet engraftment. Here, we report a robust protocol for the transplantation of islets at the extrahepatic transplantation site-the epididymal fat pad (EFP)-in a diabetic mouse model. A protocol to isolate and purify islets at high yields from C57BL/6J mice is described, as well as a transplantation method performed by seeding islets onto a decellularized scaffold (DCS) and implanting them at the EFP site in syngeneic C57BL/6J mice rendered diabetic by streptozotocin. The DCS graft containing 500 islets reversed the hyperglycemic condition within 10 days, while the free islets without DCS required at least 30 days. The normoglycemia was maintained for up to 3 months until the graft was explanted. In conclusion, DCS enhanced the engraftment of islets into the extrahepatic site of the EFP, which could easily be retrieved and might provide a reproducible and useful platform for investigating the scaffold materials, as well as other transplantation parameters required for a successful islet engraftment.

This protocol demonstrates murine islet isolation and seeding onto a decellularized scaffold. Scaffold-supported islets were transplanted into the epididymal fat pad of streptozotocin (STZ)-induced diabetic mice. Islets survived at the transplantation site and reversed the hyperglycemic condition.

פיגום נתמך השתלת איים בשומן השומן האפידידימלי של עכברים סוכרתית

Islet transplantation has been clinically proven to be effective at treating type 1 diabetes. However, the current intrahepatic transplantation strategy ...

Bioengineering

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, the role of beta-cell dysfunction in type 2 diabetes has been clearly established 2. Research progress has required methods for the isolation of pancreatic islets. The protocol of the islet isolation presented here shares many common steps with protocols from other groups, with some modifications to improve the yield and quality of isolated islets from both the wild type and diabetic Leprdb (db/db) mice. A live-cell 2-photon imaging method is then presented that can be used to investigate the control of insulin secretion within islets.

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

We present here a protocol for the isolation of islets from the mouse model of type 2 diabetes, Leprdb and details of a live-cell assay for measurement of insulin secretion from intact islets that utilizes 2 photon microscopy.

Lepr<sup&gt; Db</sup&gt; עכבר דגם של סוכרת מסוג 2: בידוד לבלב וLive- תא 2-פוטון הדמיה של איי שלמים

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, ...

Medicine

Intraportal Transplantation of Pancreatic Islets in Mouse Model

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation site in experimental islet transplantation is the kidney capsule. However, as less is known about the interaction of pancreatic islets with blood constituents, it also makes sense to utilize the portal vein approach in experimental islet transplantation.
This protocol demonstrates an intraportal islet transplantation technique in NMRI nude mice. Streptozotocin (180 mg/kg) is injected intraperitoneally to induce hyperglycemia in recipient mice. They are considered as diabetic at a non-fasting blood glucose level greater than 20 mmol/L. One day prior to transplantation, mouse pancreatic islets are isolated from the donor pancreas by collagenase digestion; a minimum of 350 islets are utilized per diabetic recipient. Depending upon the islet isolation yield, two or more donor mice are utilized per recipient. After overnight culture at 37 &#176;C, islets are administered into the recipient liver via the portal vein. After surgery, the mice are protected in red Makrolon houses and observed until are awake. This protocol maintains glycemic control for 120 days in syngeneic mice and 15 days in allogeneic mice.

Pancreatic islet transplantation is a way to achieve normoglycemia in type 1 diabetes. This article focuses on the transplantation technique through the intraportal route to maintain normal glucose levels in diabetic mice.

השתלת intraportal של לנגרהנס במודל עכבר

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation ...

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing prevalence of diabetes, both immune-mediated type 1 and obesity-linked type 2, studies aimed at delineating diabetes pathophysiology and therapeutic mechanisms are of critical importance. The &#946;-cells of the pancreatic islets of Langerhans are responsible for appropriately secreting insulin in response to elevated blood glucose concentrations. In addition to glucose and other nutrients, the &#946;-cells are also stimulated by specific hormones, termed incretins, which are secreted from the gut in response to a meal and act on &#946;-cell receptors that increase the production of intracellular cyclic adenosine monophosphate (cAMP). Decreased &#946;-cell function, mass, and incretin responsiveness are well-understood to contribute to the pathophysiology of type 2 diabetes, and are also being increasingly linked with type 1 diabetes. The present mouse islet isolation and cAMP determination protocol can be a tool to help delineate mechanisms promoting disease progression and therapeutic interventions, particularly those that are mediated by the incretin receptors or related receptors that act through modulation of intracellular cAMP production. While only cAMP measurements will be described, the described islet isolation protocol creates a clean preparation that also allows for many other downstream applications, including glucose stimulated insulin secretion, [3H]-thymidine incorporation, protein abundance, and mRNA expression.

Assaying in vitro &#946;-cell function using isolated mouse islets of Langerhans is an important component in the study of diabetes pathophysiology and therapeutics. While many&#160;downstream applications are available, this protocol specifically describes the measurement of intracellular cyclic adenosine monophosphate (cAMP) as an essential parameter determining &#946;-cell function.

שיטה לבידוד עכבר הלבלב איילט וקביעת תאית cAMP

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing ...

Observing Islet Function and Islet-Immune Cell Interactions in Live Pancreatic Tissue Slices

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared from live human and mouse pancreatic tissue embedded in agarose and cut using a vibratome. This method allows for the tissue to maintain viability and function in addition to preserving underlying pathologies such as type 1 (T1D) and type 2 diabetes (T2D). The slice method enables new directions in the study of the pancreas through the maintenance of the complex structures and various intercellular interactions that comprise the endocrine and exocrine tissues of the pancreas. This protocol demonstrates how to perform staining and time-lapse microscopy of live endogenous immune cells within pancreatic slices along with assessments of islet physiology. Further, this approach can be refined to discern immune cell populations specific for islet cell antigens using major histocompatibility complex-multimer reagents.

This study presents the application of live pancreatic tissue slices to the study of islet physiology and islet-immune cell interactions.

התבוננות בתפקוד אי ואינטראקציות תא חיסוני איון בפרוסות רקמת הלבלב חי

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared ...

Visualization of Endogenous Mitophagy Complexes In Situ in Human Pancreatic Beta Cells Utilizing Proximity Ligation Assay

Mitophagy is an essential mitochondrial quality control pathway, which is crucial for pancreatic islet beta cell bioenergetics to fuel glucose-stimulated insulin release. Assessment of mitophagy is challenging and often requires genetic reporters or multiple complementary techniques not easily utilized in tissue samples, such as primary human pancreatic islets. Here we demonstrate a robust approach to visualize and quantify formation of key endogenous mitophagy complexes in primary human pancreatic islets. Utilizing the sensitive proximity ligation assay technique to detect interaction of the mitophagy regulators NRDP1 and USP8, we are able to specifically quantify formation of essential mitophagy complexes in situ. By coupling this approach to counterstaining for the transcription factor PDX1, we can quantify mitophagy complexes, and the factors that can impair mitophagy, specifically within beta cells. The methodology we describe overcomes the need for large quantities of cellular extracts required for other protein-protein interaction studies, such as immunoprecipitation (IP) or mass spectrometry, and is ideal for precious human islet&#160;samples generally not available in sufficient quantities for these approaches. Further, this methodology obviates the need for flow sorting techniques to purify beta cells from a heterogeneous islet population for downstream protein applications. Thus, we describe a valuable protocol for visualization of mitophagy highly compatible for use in heterogeneous and limited cell populations.

This protocol outlines a method for quantitative analysis of mitophagy protein complex formation specifically in beta cells from primary human islet samples. This technique thus allows analysis of mitophagy from limited biological material, which are crucial in precious human pancreatic beta cell samples.

ויזואליזציה של מתחמי מיטוגניים אנדוגני באתרו בתאי בטא הלבלב האנושי ניצול שיטת סמיכות הקירבה

Mitophagy is an essential mitochondrial quality control pathway, which is crucial for pancreatic islet beta cell bioenergetics to fuel glucose-stimulated ...

Inguinal Subcutaneous White Adipose Tissue (ISWAT) Transplantation Model of Murine Islets

Pancreatic islet transplantation is a well-established therapeutic treatment for type 1 diabetes. The kidney capsule is the most commonly used site for islet transplantation in rodent models. However, the tight kidney capsule limits the transplantation of sufficient islets in large animals and humans. The inguinal subcutaneous white adipose tissue (ISWAT), a new subcutaneous space, was found to be a potentially valuable site for islet transplantation. This site has better blood supply than other subcutaneous spaces. Moreover, the ISWAT accommodates a larger islet mass than the kidney capsule, and transplantation into it is simple. This manuscript describes the procedure of mouse islet isolation and transplantation in the ISWAT site of syngeneic diabetic mouse recipients. Using this protocol, murine pancreatic islets were isolated by standard collagenase digestion and a basement membrane matrix hydrogel was used for fixing the purified islets in the ISWAT site. The blood glucose levels of the recipient mice were monitored for more than 100 days. Islet grafts were retrieved at day 100 after transplantation for histological analysis. The protocol for islet transplantation in the ISWAT site described in this manuscript is simple and effective.

Inguinal Subcutaneous White Adipose Tissue ISWAT Transplantation Model of Murine Islets

In this protocol, a method of murine islet isolation and transplantation into the inguinal subcutaneous white adipose tissue is described. Isolated syngeneic murine islets are transplanted into a murine recipient using a basement membrane hydrogel. The blood glucose level of the recipients is monitored, and histology analysis of the islet grafts is performed.

השתלת מודל שומן לבן תת-עורית (ISWAT) מדגם ההשתלה של איויין מורנה

Pancreatic islet transplantation is a well-established therapeutic treatment for type 1 diabetes. The kidney capsule is the most commonly used site for ...

A Simple High Efficiency Protocol for Pancreatic Islet Isolation from Mice

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other important biological functions. The islets primarily consist of five types of hormone-secreting cells: &#945; cells secrete glucagon, &#946; cells secrete insulin, &#948; cells secrete somatostatin, &#949; cells secrete ghrelin, and PP cells secrete pancreatic polypeptide. Sixty to 80% of the cells in the islets are &#946; cells, which are the most important cell population to study insulin secretion. Pancreatic islets are a crucial model system to study ex vivo insulin secretion. Acquiring high quality islets is of great importance for diabetes research. Most islet isolation procedures require technically difficult to access site of collagenase injection, harsh and complex digestion procedures, and multiple density gradient purification steps. This paper features a simple high yield mouse islet isolation method with detailed descriptions and realistic demonstrations, showing the following specific steps: 1) injection of collagenase P at the ampulla of Vater, a small area joining the pancreatic duct and the common bile duct, 2) enzymatic digestion and mechanical separation of the exocrine pancreas, and 3) a single gradient purification step. The advantages of this method are the injection of digestive enzyme using the more accessible ampulla of Vater, more complete digestion using combination of enzymatic and mechanical approaches, and a simpler single gradient purification step. This protocol produces approximately 250&#8212;350 islets per mouse; and islets are suitable for various ex vivo studies. Possible caveats of this procedure are potentially damaged islets due to enzymatic digestion and/or prolonged gradient incubation, all of which can be largely avoided by careful ad justification of incubation time.

This islet isolation protocol described a novel route of collagenase injection to digest the exocrine tissue and a simplified gradient procedure to purify the islets from mice. It involves enzymatic digestion, gradient separation/purification, and islet hand-picking. Successful isolation can yield 250&#8211;350 high quality and fully functional islets per mouse.

פרוטוקול פשוט יעילות גבוהה לבידוד איון הלבלב של עכברים

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other ...

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells that trigger secretion of three main hormones: insulin (from &#946;-cells), glucagon (&#945;-cells) and somatostatin (&#948;-cells). &#946;-Cells, which make up the majority of islet cells and are electrically coupled to each other, respond to the glucose stimulus as one single entity. The excitability of the minor subpopulations, &#945;-cells and &#948;-cells (making up around 20% (30%) and 4% (10%) of the total rodent1 (human2) islet cell numbers, respectively) is less predictable and is therefore of special interest.
Calcium sensors are delivered into the peripheral layer of cells within the isolated islet. The islet or a group of islets is then immobilized and imaged using a fluorescence microscope. The choice of the imaging mode is between higher throughput (wide-field) and better spatial resolution (confocal). Conventionally, laser scanning confocal microscopy is used for imaging tissue, as it provides the best separation of the signal between the neighboring cells. A wide-field system can be utilized too, if the contaminating signal from the dominating population of &#946;-cells is minimized.
Once calcium dynamics in response to specific stimuli have been recorded, data are expressed in numerical form as fluorescence intensity vs. time, normalized to the initial fluorescence and baseline-corrected, to remove the effects linked to bleaching of the fluorophore. Changes in the spike frequency or partial area under the curve (pAUC) are computed vs. time, to quantify the observed effects. pAUC is more sensitive and quite robust whereas spiking frequency provides more information on the mechanism of calcium increase.
Minor cell subpopulations can be identified using functional responses to marker compounds, such as adrenaline and ghrelin, that induce changes in cytosolic calcium in a specific populations of islet cells.

Here, we present a protocol for imaging and quantifying calcium dynamics in heterogeneous cell populations, such as pancreatic islet cells. Fluorescent reporters are delivered into the peripheral layer of cells within the islet, which is then immobilized and imaged, and per-cell analysis of the dynamics of fluorescence intensity is performed.

הדמיה של סידן דינמיקה באוכלוסיות משנה של תאים הלבלב איון של העכבר

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells ...